<PAGE>
 
                                          Exhibit (24)-1
                                          Unicom Corporation and
                                          Commonwealth Edison Company
                                          Form 10-K File Nos. 1-11375 and 1-1839


                               POWER OF ATTORNEY
                               -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 18/th/ day of
                                                              ------         
March, 1999.



                                        /s/ Edward A. Brennan
                                        ----------------------------------------
                                            Edward A. Brennan

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that EDWARD A. BRENNAN, personally known to me to
be the same person whose name is subscribed to the foregoing instrument,
appeared before me this day in person, and acknowledged that he signed and
delivered said instrument as his free and voluntary act, for the uses and
purposes therein set forth.

         GIVEN under my hand and the notarial seal this 18/th/ day of March,
                                                        ------                 
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                               POWER OF ATTORNEY
                               -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 18/th/ day of
                                                              ------         
March, 1999.



                                        /s/ Carlos H. Cantu
                                        ----------------------------------------
                                            Carlos H. Cantu

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that CARLOS H. CANTU, personally known to me to be
the same person whose name is subscribed to the foregoing instrument, appeared
before me this day in person, and acknowledged that he signed and delivered said
instrument as his free and voluntary act, for the uses and purposes therein set
forth.

         GIVEN under my hand and the notarial seal this 18/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 22 day of
                                                              --
March, 1999.



                                        /s/ James W. Compton
                                        ----------------------------------------
                                            James W. Compton

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that JAMES W. COMPTON, personally known to me to be
the same person whose name is subscribed to the foregoing instrument, appeared
before me this day in person, and acknowledged that he signed and delivered said
instrument as his free and voluntary act, for the uses and purposes therein set
forth.

         GIVEN under my hand and the notarial seal this 22 day of March,
                                                        --               
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 17/th/ day of
                                                              ------         
March, 1999.



                                        /s/ Bruce DeMars
                                        ----------------------------------------
                                            Bruce DeMars

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that BRUCE DEMARS, personally known to me to be the
same person whose name is subscribed to the foregoing instrument, appeared
before me this day in person, and acknowledged that he signed and delivered said
instrument as his free and voluntary act, for the uses and purposes therein set
forth.

         GIVEN under my hand and the notarial seal this 17/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 17/th/ day of
                                                              ------        
March, 1999.



                                        /s/ Donald P. Jacobs
                                        ----------------------------------------
                                            Donald P. Jacobs

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that DONALD P. JACOBS, personally known to me to be
the same person whose name is subscribed to the foregoing instrument, appeared
before me this day in person, and acknowledged that he signed and delivered said
instrument as his free and voluntary act, for the uses and purposes therein set
forth.

         GIVEN under my hand and the notarial seal this 17/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 18/th/ day of
                                                              ------         
March, 1999.



                                        /s/ Edgar D. Jannotta
                                        ----------------------------------------
                                            Edgar D. Jannotta

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that EDGAR D. JANNOTTA, personally known to me to
be the same person whose name is subscribed to the foregoing instrument,
appeared before me this day in person, and acknowledged that he signed and
delivered said instrument as his free and voluntary act, for the uses and
purposes therein set forth.

         GIVEN under my hand and the notarial seal this 18/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 17/th/ day of
                                                              ------        
March, 1999.



                                        /s/ George E. Johnson
                                        ----------------------------------------
                                            George E. Johnson

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that GEORGE E. JOHNSON, personally known to me to
be the same person whose name is subscribed to the foregoing instrument,
appeared before me this day in person, and acknowledged that he signed and
delivered said instrument as his free and voluntary act, for the uses and
purposes therein set forth.

         GIVEN under my hand and the notarial seal this 17/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOSVKI and JOHN P. MCGARRITY, and each of them, his true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 17/th/ day of
                                                              ------         
March, 1999.



                                        /s/ Richard L. Thomas
                                        ----------------------------------------
                                            Richard L. Thomas

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that RICHARD L. THOMAS, personally known to me to
be the same person whose name is subscribed to the foregoing instrument,
appeared before me this day in person, and acknowledged that he signed and
delivered said instrument as his free and voluntary act, for the uses and
purposes therein set forth.

         GIVEN under my hand and the notarial seal this 17/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Company, each an Illinois corporation, does hereby constitute and appoint
JOHN W. ROWE, JOHN C. BUKOVSKI and JOHN P. MCGARRITY, and each of them, her true
and lawful attorneys and agents, each with full power and authority (acting
alone and without the others) to execute in the name and on behalf of the
undersigned as such Director, the Annual Report on Form 10-K for the fiscal year
ended December 31, 1998 for Unicom Corporation and Commonwealth Edison Company,
to be filed with the Securities and Exchange Commission pursuant to Section 13
or 15(d) of the Securities Exchange Act of 1934, hereby granting to such
attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 22 day of
                                                              --        
March, 1999.



                                        /s/ Sue L. Gin
                                        ----------------------------------------
                                            Sue L. Gin

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that SUE L. GIN, personally known to me to be the
same person whose name is subscribed to the foregoing instrument, appeared
before me this day in person, and acknowledged that she signed and delivered
said instrument as her free and voluntary act, for the uses and purposes therein
set forth.

         GIVEN under my hand and the notarial seal this 22 day of March,
                                                        --                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public
<PAGE>
 
                                   POWER OF ATTORNEY
                                   -----------------


KNOW ALL MEN BY THESE PRESENTS:

         That the undersigned, a Director of Unicom Corporation and Commonwealth
Edison Corporation, each an Illinois corporation, does hereby constitute and
appoint JOHN W. ROWE, JOHN C. BUKOVSKI and JOHN P. MCGARRITY, and each of them,
her true and lawful attorneys and agents, each with full power and authority
(acting alone and without the others) to execute in the name and on behalf of
the undersigned as such Director, the Annual Report on Form 10-K for the fiscal
year ended December 31, 1998 for Unicom Corporation and Commonwealth Edison
Company, to be filed with the Securities and Exchange Commission pursuant to
Section 13 or 15(d) of the Securities Exchange Act of 1934, hereby granting to
such attorneys and agents, and each of them, full power of substitution and
revocation in the premises; and hereby ratifying and confirming all that such
attorneys and agents, or any of them, may do or cause to be done by virtue of
these presents.

         IN WITNESS WHEREOF, I have hereunto set my hand this 17/th/ day of
                                                              ------         
March, 1999.



                                        /s/ Elizabeth A. Moler
                                        ----------------------------------------
                                            Elizabeth A. Moler

STATE OF ILLINOIS   )
                    ) SS
COUNTY OF COOK      )

         I, Mary L. Kwilos, a Notary Public in and for said County, in the State
aforesaid, DO HEREBY CERTIFY that ELIZABETH A. MOLER, personally known to me to
be the same person whose name is subscribed to the foregoing instrument,
appeared before me this day in person, and acknowledged that she signed and
delivered said instrument as her free and voluntary act, for the uses and
purposes therein set forth.

         GIVEN under my hand and the notarial seal this 17/th/ day of March,
                                                        ------                
1999.



                                        /s/ Mary L. Kwilos
                                        ----------------------------------------
                                            Mary L. Kwilos
                                            Notary Public